feat(library/data/rbtree/lemmas): add mem_insert_of_incomp
feat(library/data/rbtree/lemmas): add mem_insert_of_incomp

leanprover/lean,digama0/lean,leodemoura/lean,dselsam/lean,digama0/lean,dselsam/lean,leanprover-community/lean,leanprover-community/lean,dselsam/lean,Kha/lean,leanprover-community/lean,leanprover/lean,leanprover/lean,digama0/lean,digama0/lean,fpvandoorn/lean,leodemoura/lean,leanprover/lean,fpvandoorn/lean,leodemoura/lean,Kha/lean,fpvandoorn/lean,digama0/lean,digama0/lean,fpvandoorn/lean,fpvandoorn/lean,leanprover-community/lean,leodemoura/lean,dselsam/lean,leanprover-community/lean,leodemoura/lean,leanprover/lean,dselsam/lean,fpvandoorn/lean,Kha/lean,Kha/lean,leanprover-community/lean,leanprover/lean,leodemoura/lean,dselsam/lean,Kha/lean,Kha/lean